This is a fun post. I love stuff like this. I don't think, however, that it's a particularly good example of "good analysis" - this analysis is clearly done eit

This is a fun post. I love stuff like this. I don't think, however, that it's a particularly good example of "good analysis" - this analysis is clearly done either by (a) someone who isn't fully aware of all of the various strategies and nuances of NFL football, or (b) someone who is aware of such things but was in a rush to get this post written. There's just too much missing information to draw any conclusions such as those drawn by OP. A trick's play's success rate is based on many factors. Saying that the down number is the primary factor is like rating a woman's attractiveness by how smart she is. Such a rating would, of course, give you false positives and negatives because it represents only part of the whole. A trick play's success rate depends on down number, position on the field, the clock, defensive tendencies, score, weather, field conditions, player injuries, and more. For example, a flea flicker isn't going to be attempted as often in really bad weather, or when you are up by four touchdowns, or when the main player who is the ultimate receiver of the ball (the "flea", perhaps?) is out of the game due to injury. So I like this sort of analysis but it's completely useless due to its incompleteness. But I still am glad OP shared because I like seeing all the thoughts, functions, and so forth.